Over the recent years, mobile terminal units such as mobile phones have been improved in functionality. For example, there have been developed mobile phones with which it is possible to enjoy not only audio communications but also communications using texts or images, such as sending/receiving electronic mails and browsing the Internet. To make text information or image information viewable on the mobile phones, upsizing of displays has been demanded. At the same time, smaller and lighter terminals have been demanded to make the terminals easy to carry.
To meet the demands, there have been known techniques for upsizing a display area of a display while keeping the body of the mobile terminal small in size.
For example, Publication 1 discloses a mobile terminal unit that is constituted of a main unit and a sliding section. The main unit includes a key operation section and a small liquid crystal display section. The key operation section is provided on a front surface of the main unit, and a user operates keys to input predetermined information. On a front surface of the sliding section, a large liquid crystal display section is provided to display predetermined information for the user. The main unit and the sliding section are each provided with a sliding mechanism in such a manner that the sliding section is slid to move to a rear surface of the main unit.
Publication 2 discloses a mobile phone including a first liquid crystal display section and a second liquid crystal display section. The second liquid crystal display section is mounted inside or on a rear surface section of the mobile phone in such a manner that the second liquid crystal display is not removable and can be freely pulled out and retracted. When taken out, the second liquid crystal display section faces the same direction as the first liquid crystal display section does, and forms, along with the first liquid crystal display section, a multi liquid crystal display section.
Publication 3 discloses a mobile phone including a liquid crystal display section. An external surface of the liquid crystal display section is covered by a transparent plate. The mobile phone also includes a display sheet unit mounted on one side of a main unit of a telephone. The display sheet unit includes a winding shaft and a flexible display sheet. The winding shaft rotates forward and backward freely with electric driving power. The flexible display sheet is wound around the winding shaft. The flexible display sheet is provided so as to come in and out freely between the transparent plate and the liquid crystal display section, when the winding shaft rotates forward and backward. A front surface of the display sheet is formed on a mirror surface or a pattern display surface on which a desired pattern is drawn.
Publication 4 discloses a mobile electronic device including an inner screen to display information. A feature of the electronic device is an outer screen that is configured so as to receive information from the electronic device and to allow the information to be displayed on an electronic optical medium.
According to the foregoing publications, it is possible to provide the mobile terminal unit with a large display so that displaying on a large screen is possible even with a small unit.    [Publication 1] Japanese Unexamined Patent Publication No. 2003-169120 (Publication Date: Jun. 13, 2003)    [Publication 2] Japanese Unexamined Patent Publication No. 2003-198683 (Publication Date: Jul. 11, 2003)    [Publication 3] Japanese Unexamined Patent Publication No. 2003-198689 (Publication Date: Jul. 11, 2003)    [Publication 4] Published Japanese Translation of PCT International Publication for Patent Application, Publication No. 2004-536475 (Publication Date: Dec. 2, 2004)